p53 promotes ZDHHC1-mediated IFITM3 palmitoylation to inhibit Japanese encephalitis virus replication

Abstract

The tumor suppressor p53 as an innate antiviral regulator contributes to restricting Japanese encephalitis virus (JEV) replication, but the mechanism is still unclear. The interferon-induced transmembrane protein 3 (IFITM3) is an intrinsic barrier to a range of virus infection, whether IFITM3 is responsible for the p53-mediated anti-JEV response remains elusive. Here, we found that IFITM3 significantly inhibited JEV replication in a protein-palmitoylation-dependent manner and incorporated into JEV virions to diminish the infectivity of progeny viruses. Palmitoylation was also indispensible for keeping IFITM3 from lysosomal degradation to maintain its protein stability. p53 up-regulated IFITM3 expression at the protein level via enhancing IFITM3 palmitoylation. Screening of palmitoyltransferases revealed that zinc finger DHHC domain-containing protein 1 (ZDHHC1) was transcriptionally up-regulated by p53, and consequently ZDHHC1 interacted with IFITM3 to promote its palmitoylation and stability. Knockdown of IFITM3 significantly impaired the inhibitory role of ZDHHC1 on JEV replication. Meanwhile, knockdown of either ZDHHC1 or IFITM3 expression also compromised the p53-mediated anti-JEV effect. Interestingly, JEV reduced p53 expression to impair ZDHHC1 mediated IFITM3 palmitoylation for viral evasion. Our data suggest the existence of a previously unrecognized p53-ZDHHC1-IFITM3 regulatory pathway with an essential role in restricting JEV infection and provide a novel insight into JEV-host interaction.